Conventionally, there have been known surveillance recorders and their methods for recording a surveillance picture taken by a surveillance camera or the like. A surveillance recorder is required to be able to detect a person's image efficiently and appropriately from a recorded surveillance picture. Japanese Published Patent Application No. 2003-46911 discloses a surveillance recorder that chooses from a surveillance picture and stores a standard person's image in order to allow a person's image to be appropriately searched for. In the device described in this patent document, when a person is to be detected, matching is performed with a standard front face template, and a face image of a shot showing the greatest similarity in the matching is chosen as an image suitable for storage. In another face image choice method, an image having the largest number of pixels that belongs to a skin color region in a color space is chosen as an image suitable for storage.